In general, passes are valid on all trains operated by national rail companies; more and more private rail newcomers accept the pass. In some countries (Italy, Spain and Switzerland in particular) you'll find regional or private companies that don't accept Interrail or Eurail passes, although many of them offer up to 50% discount for passholders.
Depending on the country, the pass may not only cover intercity rail, but also some public transit and ferry services, but mind that not all railway companies or train services may be covered. The complete list of train operators accepting passes can be found at the Interrail or Eurail^{[dead link]} website.

Extra fees can apply for making reservations, fast trains, couchettes and sleepers. The exact rules vary by country and can be very complex, so ask in advance, but a rule of thumb is that anything which requires a reservation in advance (shown with a black [R] in a box in schedules) will require a surcharge. In peak season on popular routes seat reservations are definitely worthwhile.

Night trains. Travelling overnight has gotten more and more costly and less worthwhile for passholders; the fees for couchettes are usually higher or even much higher for passholders. If booked well in advance, a non-refundable discount ticket (including the fee for a berth) might be cheaper than the mere berth fee according to the special tariff applied for passholders. If you particularly feel like passing a night sitting upright and perhaps getting no sleep at all, the "normal" seats most sleeper trains also carry might be a good deal, however

High-speed trains such as TGV, Thalys, ICE (only lines to France), Eurostar, Italia, Cisalpino, X2000, AVE and Talgo 200, may require pass holders to pay supplements, particularly in Spain, Italy and France, which makes rail passes for these countries rarely worthwhile (see Infobox). The One Country Premium Passes, which included the supplements, were discontinued in 2019.

Eurail and Interrail passes are valid on Eurostar crossings between UK and mainland Europe, but a reservation is compulsory (€30 fee between the UK and France or Belgium, €35 for the Netherlands, and €8 more for 1st class on both routes) and can be made from 12 weeks in advance here; the pass must be valid for travel in the continental departure or arrival country, i.e. for either France (Paris–London route) or Belgium (Brussels–London route).

You'll find an introduction to reservations on the Interrail website. Basically, reservation conditions are the same for both Eurail and Interrail, but as the participating countries differ, the corresponding website should be consulted to avoid getting misled – for detailed information about reservation see the Interrail resp. Eurail section.

Mind: A vacant seat is not guaranteed unless you make a reservation!

On both Interrail and Eurail, ferries between Ireland and France, Italy and Greece as well as many ferries in the Baltic sea between Denmark, Germany, Sweden and Finland, are discounted, while a select few are free (albeit still subject to seasonal surcharges and port fees). Many boat rides on Switzerland's lakes are free as well. With a flexible pass and an ambitious itinerary, ferry travel can be a smart choice on the majority of routes where only a discount applies, as only free crossings use up a travel day. Bear in mind though, that on overnight sailings a reclining seat or cabin/berth, which is often an obligatory extra, is sometimes not subject to the same rate of reduction the basic fare is, and can be a significant hidden expense.

As of January 2019 the sale of Plus variants of Interrail one-country passes for Greece and Italy (including free ferry crossings between the two countries) has been discontinued. Now, on most lines you get free deck passage if the Eurail/Interrail pass is valid in both Italy and Greece. If the pass is valid in either Italy or Greece, a 30% discount is granted.

Also a special Greek Islands Pass is offered by both Eurail and Interrail and is available for 5 or 6 trips within one month. In the 6-trip pass 2 trips between Italy and Greece are included free of charge. Note that some conditions differ between the Interrail and Eurail pass. For details see Eurail Greek Islands Pass resp. the Interrail Greek Islands Pass.

The exact conditions vary according to the ferry operator.

Always check the daily schedules during the specific week of travel. Some ferries cease operation in the off-season altogether, while others reduce service to one round-trip daily, from several trips a day during peak season.

Travel days are generally counted from midnight to midnight.

Any mention of "month" herein does not mean calendar month, but any month-like time span starting on any day of a month. For example, a pass can be valid from January 1st to January 31st (31 days), February 4th to March 3rd (28 resp. 29 days), or June 15th to July 14th (30 days). One-month passes last longer when starting (on any day) within a 31-day calendar month.

Concerning Eurail/Interrail, the former 7pm rule has been abolished as of 2019. If you take a train before midnight (e.g., 22:37 to 05:21 the next day), only the day of departure must be filled in. For more details see the Eurail/Interrail Good to know section.

Unless otherwise noted, these all apply to all kinds of passes.

Border train stations are covered by passes outside the countries they are issued for as well. For example, Salzburg and Kufstein in Austria are considered border stations of Germany and therefore are covered by German railpasses. Likewise Passau and Lindau, among other minor border stations in Germany, as well as Buchs SG in Switzerland and Sopron, Szentgotthárd in Hungary are considered Austrian border stations.

Switching between classes. Passengers with 1st-class passes may travel in 2nd-class compartments at any time. Those with 2nd-class passes can pay the difference (usually 50%) between 1st- and 2nd-class point-to-point fares in order to upgrade to 1st class.

Better off with regular tickets? Check the actual prices of normal point-to-point tickets. In some cases your journey can be cheaper with them than with a pass. Especially in eastern European countries a pass tends to be bad value for money as the local cost of point-to-point tickets is very low. In Western Europe you may be able to cobble together an itinerary with non-refundable, non-changeable train-specific discount tickets (valid on a certain train only) that works out cheaper than a pass would, but this lacks the flexibility and sense of adventure that makes Interrail unique.

In some countries national discount cards may be an alternative, especially when undertaking few trips, in particular in Austria, where they are sold at a very low price to young people under the age of 26 and families as well as to seniors from the age of 63, which facilitate point-to-point tickets at half price.

At Trainline's websites – Trainline.com or Trainline.eu – a ticket agency which claims to offer best-price tickets from whichever railway company available, you can check out regular fares and those non-refundable non-changeable train-specific discount tickets.

Many city-to-city connections are listed on the ACPRail website showing travel details and where you also can check out regular fares.

Both Eurail and Interrail provide a variety of rail passes which cover travel in most countries in Europe, which comprise all European countries with railway services except Albania, Belarus, Kosovo, Moldova, Russia, and Ukraine.

Eurail/Interrail passes cover travel in a total of 35 countries:

The so-called Benelux country group, comprising Belgium, the Netherlands and Luxembourg, is always treated and counted as one country; passes are not available for any single country out of this group.

Mind that Northern Ireland is not covered by One Country Passes for Great Britain, but rather is covered by passes being valid in the Republic of Ireland.

The actual list of countries participating in Eurail can be checked here and of those participating in Interrail can be checked here, but mind that the lists are not always up-to-date and the mini-states are not mentioned.

Railway and ferry companies. The list of all participating companies can be found at the Eurail^{[dead link]} resp. Interrail website.

The previous convoluted zone system has been abolished, and there are now only two basic types of passes, which are available for a variety of travel days:

• Global Pass, which allows travel in all participating European countries (mind the different countries covered by Eurail and Interrail).
  

You can choose between "flexible" passes (for non-consecutive days) and "continuous" passes (for consecutive days):

- flexible passes:

• 4 days within 1 month (not available at all European train stations)
• 5 or 7 days within 1 month
• 10 or 15 within 2 months

- continuous passes:

• 15 or 22 days
• 1, 2 or 3 months

• One Country Pass, which covers one or, in some cases, a group of adjoining countries. Not for all participating countries does a one-country pass exist.

This pass is available in "flexible" variants only:

• 3, 4, 5, 6 or 8 days within 1 month.

The Global Pass and One Country Pass offer the same train services in the countries covered by the pass chosen, for details check the Eurail site^{[dead link]} or the Interrail site.

All Eurail/Interrail passes are available for 1st or 2nd class, with the exception of Norway: 2nd class only because of the absence of 1st-class train accommodation.

Pricing naturally depends on the exact variation as well as the age category.

Although the reservation requirements should be the same, in order to be sure look at the corresponding Eurail or Interrail site. Below you'll find helpful information about reservations on the corresponding website:

Determining the starting date. There is a big difference between Eurail and Interrail passes:

• Eurail passes are generally valid within 11 months from date of issue, but need to be activated either at a train station or online at the Eurail website. On activation, the first travel day has to be fixed, thus determining the effective period of validity.
• Interrail passes are also valid within 11 months from date of issue, but the first travel day has to be fixed when the pass is ordered. However, this limitation does not apply when buying the pass in the new mobile format.

Prices usually rise every year to reflect the changes in exchange rate and point-to-point fares. Usually, there are promotion months in March and December, when the prices of most Interrail passes are reduced by 15%; the Eurail homepage advertises even reductions between 15% (One Country Pass) up to 45% (Global Pass). As passes generally can be purchased 11 months in advance, if you got your travel plans fixed it would make sense to buy passes months ahead of the journey.

Travel days. Usually travel days are counted from midnight to midnight. The former 7pm rule, which counted only the next day when you boarded a direct overnight train or ferry after 7pm, has been abolished as of January 2019 and does not apply anymore.
The new regulation determines that the day of departure is counted in any case and you can finish the travel on a direct night train until you'll arrive without using another day. But if you have to change to another train on the next day in order to reach your destination, the next day is counted as one more day.

Ferries. Concerning overnight ferries the regulation is more generous: You can choose whether you want the day of departure or arrival to be counted. And for discounted ferry trips no travel days need to be used, simply showing your pass gets you the discount as long as the pass has not expired – even if all travel days have been used up.

Extra benefits. Passholders may obtain extra benefits like discounts on ferry fares or City Cards. Got curious? Here you can check the Eurail benefits^{[dead link]} and the Interrail benefits.

The European East Pass permits unlimited travelling on all trains of the national railway companies of Austria, Hungary Czech Republic, and Slovakia, on 5 up to 10 days. It is available only to non-residents of these countries. Details can be found here^{[dead link]}.

The Central European Triangle Pass is not a typical pass, but a special combined ticket for hopping between the cities of Vienna, Prague and Budapest or Vienna, Prague and Salzburg. This ticket is available for 2nd class only and can be purchased only by non-residents of the four countries.
The ticket is valid for one month. Travel can start in any city, going to the others in any order. All trains of the national companies (ČD, MÁV, ÖBB) can be used in the 2nd class without supplement. Reservations are not included, which are recommended for some trains, especially those between Vienna and Budapest. But mind that you may get on and off the trains only in these cities, no interruption is allowed at intermediate stops. More information can be found here.

Although the slow and infrequent trains are by no means the most efficient way of traveling in the Balkans (this is by any standard the bus), it is one of the more comfortable and scenic.

The Balkan Flexipass allows unlimited rail travel for 3, 5, 7, 10 or 15 days of rail travel within 2 months in Bulgaria, Greece, Montenegro, North Macedonia, Romania, Serbia and Republika Srpska (Serbian entity of Bosnia-Herzegovina) as well as Turkey (including the Asian part). The pass is available for 1st or 2nd class. For more information see the Rail Europe, ACPRail^{[dead link]} and Rail.cc websites, where also ordering is possible.

Caveat is that trains in the Balkans are already really cheap and that it only pays off for longer distances. Another thing to take into account is that the rail network in the Balkans is a lot less dense than in the rest of Europe, so some places simply cannot be gotten to by rail.

ČD (České dráhy), the national Czech railway operator, offer an All-Day Ticket, a one-day pass, valid on one day for all ČD trains of any category running on the network. The All-Day Ticket is available for any one region or for the whole country. The price of the All-Day Ticket valid in the whole country is CZK 699 (€29,40; as of March 2023).
The All-Day Ticket is sold to anybody independently of residence.

German Rail Pass^{[dead link]} for travelling in the whole country on 3, 4, 5, 7, 10 or 15 consecutive or flexible days within 1 month. The pass is available for 1st and 2nd class.

Discounts are granted to groups of 2 travellers („Twin“ category) and youth 12<28. Up to 2 children 6<12 per adult travel on a free Child pass; additional children or those travelling alone require a youth pass; children under 6 years of age travel for free if no reservations are needed.

The German Rail Pass is not made available to residents of any European country, Turkey and Russia.

For those planning to stay and travel long-distance within Germany for longer periods, Deutsche Bahn (DB) also offers an annual Bahn 100 card. It costs €4,339 (standard class) and €7,356 (first class) for up to a year of unlimited rail travel (including on high-speed ICE trains) without the need for reservation. In addition, you may use local public transport to or from any railway station on the DB Network. However for journeys between Germany and an international point, the Bahn 100 card might not cover the segments outside Germany; they will instead be covered by standard tariffs of the country in question.

BritRail Passes^{[dead link]}: Most passes are available as mobile-phone pass (M-Pass), there are some regional variants available as M-Passes only:

• BritRail Pass (covering all of Great Britain), BritRail England Pass, BritRail London Plus Pass', BritRail South West Pass, BritRail Spirit of Scotland Pass (covering all of Scotland), BritRail Central Scotland Pass, BritRail Scottish Highlands Pass.

• Northern England: North of England Rover Pass, North of England City Experience Pass

• Scotland variants: ScotRail Spirit of Scotland M-Pass, ScotRail Central Scotland Rover M-Pass, ScotRail Scottish Grand Tour M-Pass, ScotRail Highland Rover M-Pass, ScotRail Edinburgh Days Out M-Pass, ScotRail Glasgow Days Out M-Pass

If you click on any pass in the list above you'll obtain all detailed information concerning that pass.

The maps which show where the different BritRail passes are valid can be found here^{[dead link]} and here^{[dead link]}.
Mind that Northern Ireland is not covered by any of the BritRail passes! For travelling in Northern Ireland you have to use an Interrail/Eurail pass valid in Ireland which covers the networks of the Republic of Ireland as well as of Northern Ireland.

The BritRail passes are available for consecutive and non-consecutive days. The number of selectable days varies depending on the network and may be different for Europeans and non-Europeans. Most passes do not allow travelling before 9:00am.

All passes are available for 1st and 2nd class. The prices of the 1st-class passes have been adjusted to the fact that some trains do not have 1st-class accommodations.

Discounts are usually granted to groups of 3-9 people (up to 20%), youth 16<26 (20%), seniors ≥ 60 (up to 15%); one child 5<16 per adult or senior travels on a free Child pass, for each additional child the half adult fare has to be paid; children under 5 years of age travel for free if no reservations are needed.
For most passes low-season discounts (up to 20%) are offered for travel between January 1st and February 28th as well as November 1st and December 31st.

The official website of BritRail is Britrail.com managed by National Rail, and more detailed information is provided by the authorized retailers^{[dead link]} where the passes can be ordered. The passes are available at agencies only abroad, and generally online or as mobile-phone app (M-Pass).

Eligibility. The information about who is eligible to BritRail passes is confusing. While Britrail.com says that all passes are exclusively sold to non-UK residents, BritRail.net affirms that North of England Passes and ScotRail Passes are available to anyone including UK residents, as is explicitly mentioned.

The Trenitalia Pass is available to Non-Italian citizens residing outside Italy. The pass does not allow unlimited trips on the days on which it is valid. Instead, the pass can be used only for the number of trips chosen at purchase.

With this pass you can travel on the "Frecce" high-speed trains and on the FrecciaLink service (providing connections) as well as on Intercity, Intercity Night and EuroCity Italy–Switzerland trains (on domestic routes within Italy), all being operated by the Trenitalia railway company. By other railway companies the pass is not accepted. Even regional and local trains operated by Trenitalia cannot be used with this pass.

In contrast to Eurail/Interrail passes, the Trenitalia Pass does include seat reservation fees. Nevertheless, reservations are mandatory, but free of charge.

The pass is available for

• 3 or 4 trips within 7 days
• 7 trips within 15 days
• 10 trips within 1 month

and also for three classes
 - Easy, Comfort and Executive where Easy permits access to 2nd class only.

Mind that a trip is defined as a ride on one single train without changing. Changing to another train (except to FrecceLink) reduces the number of remaining trips. Thus, the journey has to be planned meticulously in order to make best of use the "trips".

Prices are differentiated between the same age groups as with Eurail/Interrail. Also, the regulations concerning accompanying children are the same.

All prices and the conditions of use can be found on the Trenitalia website.

Renfe Spain Pass is an untypical pass permitting travel on Renfe's long-distance (AVE) and medium-distance trains on 4, 6, 8 or 10 trips (not days!) within 1 month. It is available for 1st class ("preferente") or 2nd class ("turista"). A trip is defined as a ride on one single train without changing, for each train a reservation is required which can be obtained only at train stations (no extra fee, included in the pass). The "generosity" they offer is to permit using commuter trains for free within the time span of 3 hours before getting on and 3 hours after getting off the long-distance train chosen by you. The terms of use are highly insufficiently explained on Renfe's website, but get clearer here.
The Renfe Spain Pass is not made available to residents of Spain.

Swiss Travel Pass for travelling in the whole country on 3, 4, 8 or 15 consecutive or flexible days within 1 month. The Swiss Travel Pass also covers premium panorama trains (except for reservation fees) and most of regional and local public transportation (including buses, trams and boats) and offers discount on privately operated cable cars and funiculars. Free admission to over 500 museums is included as well.

The pass is available for 1st and 2nd class. A discount is granted to young people under 26 years of age. The Swiss Travel Pass is not made available to residents of Switzerland and Liechtenstein.

An overview on passes and discount cards for tourists is given here. There are also day-passes and week-passes available for certain regions of Switzerland including not only train services, but also regional and local public transport within the region.